A simplified method to determine [99mTc]TRODAT-1 in human plasma

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Neuroscience

Background:

• [99mTc]TRODAT-1 is crucial for imaging dopamine transporters (DAT) in neurodegenerative diseases like Parkinson's.
• Accurate quantification of [99mTc]TRODAT-1 in plasma is essential for reliable SPECT imaging.
• Existing methods for plasma [99mTc]TRODAT-1 measurement can be complex.

Purpose of the Study:

• To develop a simplified, quantitative method for measuring unchanged [99mTc]TRODAT-1 in human plasma.
• To establish a reliable alternative to HPLC for clinical SPECT imaging applications.
• To validate a new solvent extraction technique for [99mTc]TRODAT-1 quantification.

Main Methods:

• Investigated plasma components after [99mTc]TRODAT-1 injection: hydrophilic, lipophilic metabolite, and unchanged tracer.
• Developed a solvent extraction method using cyclohexane to separate [99mTc]TRODAT-1 from its metabolite [99mTc]BAT.
• Compared the new extraction method with HPLC using human plasma samples from SPECT studies.

Main Results:

• Cyclohexane demonstrated high extraction yield for [99mTc]TRODAT-1 (76.06%) and low extraction for [99mTc]BAT (2.43%).
• The extraction method accurately reflected theoretical ratios of [99mTc]TRODAT-1 and its metabolite.
• Results from human subjects showed excellent agreement between the solvent extraction and HPLC methods.

Conclusions:

• The developed solvent extraction method is a simple, reliable, and accurate technique for quantifying [99mTc]TRODAT-1 in human plasma.
• This method facilitates the clinical application of [99mTc]TRODAT-1 for quantitative DAT imaging via SPECT.
• The improved method supports more accessible diagnosis and monitoring of CNS neurodegenerative diseases.